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You have completed (UPI) Chapter 11: Managing Errors, Debugging, and Handling Events in JavaScript!

Instruction

Update older browsers

If you are using an older browser that does not yet implement let or class, for example, you should update to a more recent browser version that does support these new language features.

"use strict";

class DocArchiver {}
// SyntaxError: class is a reserved identifier
// (throws in older browsers only, e.g., Firefox 44 and older)